Organopolysiloxane compositions which remain stable and free flowing during shelf storage in a sealed condition, but when exposed to the ambient air, cure into rubbery elastomers at room temperature under the action of humidity are known in the art as RTV organopolysiloxane compositions. They have been widely used as sealants, coatings, and adhesives in building, machinery, electrical and other industrial fields.
RTV organopolysiloxane compositions are generally classified into acetate type, oxime type, alcohol type, hydroxyamine type, and amine type depending on the type of compound to be eliminated. The compositions of acetate, oxime, hydroxyamine, and amine types are undesirably corrosive to the surrounding metal while the compositions of alcohol type become unlikely to cure after long-term storage.
To overcome these drawbacks, Japanese Patent Application Kokai No. 11953/1979 proposes an RTV organopolysiloxane composition which is shelf stable and does not corrode the surrounding metal. This composition, however, tends to yellow under the influence of ultraviolet rays and heat and does not cure under acidic conditions since the curing catalyst is a guanidine compound.
An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art RTV organopolysiloxane compositions and to provide a novel and improved RTV organopolysiloxane composition which is non-corrosive to metals, shelf stable, discoloration resistant, and curable under acidic conditions.